1. Field of the Invention
The present invention relates to a computer system, a subordinate device, and a power supply control method. In particular, the present invention relates to a computer system, a subordinate device, and a power supply control method which are suitable for an efficiency-increase and a power saving in a power-off operation.
2. Description of the Related Art
In a computer system such as a disc array system, common is a configuration in which a main device such as a host computer and a subordinate device such as a disk array device are connected by a prescribed interface. In such a computer system, when turning off the system, for example, due to a maintenance work, the sequence of cutting off a power supply of each device that composes the system may be specified. In the case of the disc array system or the like, the power supply of the disk array device in usual circumstance always needs to be on while the host computer is running. Therefore, in the case of the disc array system or the like, the power-off of the disk array device must be started after completion of the power-off of the host computer.
When such a work of power-off is performed manually, an operator first performs an operation for power-off of the host computer, thereafter, waits for the complete power-off of the host computer, and then performs the operation for power-off of the disk array device or the like, after confirming the complete power-off of the host computer. However, a waiting time of several minutes may be required after the operation of power-off of the host computer is performed until the completion of power-off of the host computer. Such a waiting time can become a factor which reduces working efficiency.
On the other hand, the operator cannot always perform the operation for power-off of the disk array device or the like, immediately after completing the power-off of the host computer, when performing another work in the waiting time in order to use such a waiting time effectively. Therefore, in spite of the power-off of the host computer, a power-on state of the disk array device, or the like, may continue. In this case, a wasteful power will be consumed until the operator performs the operation for power-off of the disk array device, or the like.
As a method of solving such a problem, for example, in Unexamined Japanese Patent Application KOKAI Publication No. H11-305879 (hereinafter referred to as “Patent Literature 1”), a method of interlocking a power supply control using an uninterruptible power supply device (a so-called UPS) is disclosed, and in Unexamined Japanese Patent Application KOKAI Publication No. 2007-72600 (hereinafter referred to as “Patent Literature 2”) for example, a method of interlocking a power supply control using a special interface is disclosed.
However, in the case of adopting the method disclosed in Patent Literature 1, there is a problem that a configuration thereof becomes complicated and a cost increases since it is necessary to build the system incorporating the UPS. In the case of adopting the method disclosed in Patent Literature 2, there is an inconvenience that there is no versatility, and a construction or an alteration of the system cannot be performed easily since the interface for exclusive use is used in order to make the power supply control be interlocked.
The present invention has been made in view of the above-mentioned actual conditions, and an object of the present invention is to provide a computer system, a subordinate device, and a power supply control method which can perform a power supply interlocking control easily.